<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <button>E</button>
    <script>
        /* 
         1.  clearTimeout  清除定时器
        */

        console.log('炸弹已安放');
        var time1=setTimeout(function(){
            console.log('炸弹已爆炸');
        },7000);

        var btn=document.querySelector('button');
        btn.addEventListener('click',function(){
            console.log('炸弹拆除成功');
            clearTimeout(time1)
        })
    </script>
</body>
</html>